Middlesex County is preparing for its first real estate reassessment in four years, with some home values up by as much as 40%. The county, along with Mathews and King & Queen, issued a request for proposals earlier this month to hire a firm for the reassessment. Officials are aiming to review bids by mid-June and vote on a contract at their July 8 meeting. Some supervisors raised concerns about lost tax revenue due to the rising property values between assessments.